Worked examples
Two examples
Example 1
A passage written for this example (its sentences are numbered)
Sentence 3: “Most monarchs live only a few weeks, but the butterflies that make the fall journey live for about eight months.”Is this sentence the main idea of the passage, or a detail?(1) Every fall, monarch butterflies from the eastern United States and Canada fly as far as 3,000 miles to spend the winter in the mountains of central Mexico. (2) There they gather by the millions on fir trees. (3) Most monarchs live only a few weeks, but the butterflies that make the fall journey live for about eight months. (4) No single butterfly makes the whole round trip; it takes several generations to get back north in the spring. (5) The monarch’s migration is one of the longest journeys made by any insect.
- Read the whole passage once before you look at the one sentence. Then ask: what is every sentence about?
- Sentence 1 tells how far the butterflies fly. Sentence 2 tells where they gather. Sentence 4 tells that the trip back takes several generations. Sentence 5 says the migration is one of the longest journeys made by any insect.
- Every sentence is about the long journey. Sentence 5 says that in one sentence, so sentence 5 is the main idea.
- Sentence 3 gives one fact: how long the travelling butterflies live. It is interesting, and it is true, but it is one piece of the passage. It is a detail.
- A common mistake: a surprising fact can feel like the main point. But it covers only one part of the passage, so calling it the main idea is choosing an answer that is too narrow.
Answer: A detail
Example 2
A passage written for this example (its sentences are numbered)
Which sentence states the main idea of the passage?(1) When your body gets hot, you sweat. (2) Sweat is mostly water, pushed out through tiny openings in the skin. (3) As the water evaporates, or turns into a gas, it carries heat away from the skin. (4) This is why a breeze feels good on a hot day: moving air makes sweat evaporate faster. (5) Sweating is one of the main ways the body keeps itself from getting too hot.
- Say in a few words what each sentence does.
- Sentence 1: hot bodies sweat. Sentence 2: what sweat is. Sentence 3: how evaporating sweat carries heat away. Sentence 4: why a breeze feels good. Sentence 5: sweating keeps the body from getting too hot.
- Sentences 1 to 4 are all parts of one story: how sweating cools the body. Which sentence covers all of that? Sentence 5.
- The main idea is often the first sentence, but not always. Here it comes last, after the details that support it.
Answer: Sentence 5
Where this is taught: Science Practices, part 2: Reading a science passage · Look Again Quiz 1: Reading Science
In your Kaplan book: Unit 4, Chapter 1, Lesson 1: Comprehend Scientific Presentations · Map of the Terrain, topic 1: Reading science
The drill
Ten questions
How many:
Read what is in the box first, if there is one. Then tap your answer; a few questions ask you to choose words from a drop-down instead, the way the GED test does. Press Check my answers at the bottom.Read what is in the box first, if there is one. Circle your answer; where there are brackets, circle the choice that fits. The answer key, with the reasoning, is on the last page.